Research On Active Reconfiguration Strategy Of Distribution Network For Open Capacity Improvement

The distribution network is the key infrastructure for effective power supply.It has an irreplaceable role in meeting the electricity demand of residents and ensuring the normal production of enterprises.In recent years,with the rapid development of cities,the network structure has become increasingly complex,and users have higher and higher requirements for power supply reliability and power quality.At the same time,the load is increasing and the demand for installation is more frequent.As a result,the pressure on power supply companies to adjust the operation mode of the power grid,tap the power supply potential of the distribution network,and enhance the safety of operation is also increasing.Under this background,it is of great significance to study the optimal operation and control strategy of distribution network.In this paper,the generalized Benders decomposition algorithm is used as the research tool,and two key scientific issues,network reconfiguration and open capacity evaluation,are deeply studied and discussed in order to provide useful reference for the operation and research of distribution network.The specific research work is as follows:1.The problem of distribution network reconfiguration considering power supply reliability is studied.A computational strategy based on generalized Benders decomposition is proposed,which solves the problem that the traditional model is oversimplified and the algorithm cannot effectively deal with complex constraints.The basic idea is to introduce reliability constraints such as voltage operating range and line power flow restrictions into the network reconstruction model to form a comprehensive network reconstruction optimization problem.Then the GBD algorithm is used to disassemble the formed problem into two problems and calculate separately.The master problem is used to determine the switch state,and the sub-problem is responsible for checking its feasibility.The results of the test are returned in the form of Benders cuts.The optimal solution of the original problem is obtained by iterating alternately between the master and subproblems.2.The open capacity evaluation of distribution network is studied,and the generalized Benders decomposition-dichotomy approximation bi-level hybrid algorithm is proposed,which solves the problems of equivalent linear transformation of switching operation constraints in the evaluation model and too optimistic evaluation results.The switching operation,power flow and N-1security constraints are introduced into the calculation of power supply capacity of distribution network,and then the auxiliary variables are introduced to transform the absolute value operation of switching constraints into equivalent linear transformation.An open capacity evaluation model of distribution network considering N-1 constraints and network reconfiguration is established.The model takes into account the influence of system operation constraints before and after faults.It is suitable for various connection forms of distribution networks,such as single connection and multi-connection.It has the characteristics of strong adaptability,high calculation accuracy and good reliability of results.To solve the model,a two-level hybrid algorithm based on generalized Benders decomposition and bipartite approximation is proposed.The algorithm utilizes the ideas of upper approximation,lower test and two-level interaction to shrink the solution space until the optimal solution of the whole problem is obtained.3.Based on the above models and methods,this paper uses a standard example and an actual distribution system for multi scenario analysis and comparison.The example results verify that the network reconfiguration strategy proposed in this topic can effectively improve the power supply reliability of the distribution network and ensure the safe and stable operation of the system.At the same time,the proposed openable capacity calculation method is helpful to tap the power supply potential of the distribution network to the greatest extent,and plays an important role in delaying the system construction investment and improving the network operation mode.