Research And Application On Theoretical Line Loss Computing Technology For Integrated Medium And Low Voltage Distribution Network

Distribution network is the weak link of the power grid currently.Serious distribution network loss is an important problem.The key step of the solution is to calculate the theoretical line loss accurately.But the traditional methods have low precision and can not accurately reflect the actual line loss situation.Therefore,the methods with high precision has been paid more attention.Power flow method is one of them.In order to improve the calculation accuracy of theoretical line loss,this paper studies the application of power flow method on the calculation of theoretical line loss,and design theoretical line loss computing software for integrated medium and low voltage distribution.In the aspect of theory,the single-phase power flow model of the Fast Ybus Gauss method and the Current Injection Newton method are studied in this paper,and the application method on the theoretical line loss calculation is proposed.Then the single-phase power flow model is extended to the three-phase power flow model.Based on the second chapter,the application of three-phase power flow on theoretical line loss calculation is proposed.The fast Ybus Gauss method uses phase components to better deal with three-phase asymmetry problem.The Current Injection Newton method uses Cartesian coordinate system for programming.The two power flow methods introduce the processing of the PV node in detail,because the PV node needs to increase the constraint equation to meet the power flow calculation condition.In practical application,this paper combines the power flow method with database interface technology,overloading algorithm and sparse technology,to designs the line loss calculation software for integrated medium and low voltage distribution.The software can get the theoretical line loss of each line in the system in detail,and improve the accuracy of theoretical line loss to a great extent.In the end,the IEEE single-phase and three-phase standard examples are used to verify the correctness of the algorithm.The 33-point distribution network system is used to verify the influence of three-phase load asymmetry on the theoretical line loss.The practical example is used to verify the practicality of the software.The results show that the algorithm can converges fast and stably,and deal with a variety of different systems.