Research on calculation method of electric distance for AC and DC power system

Electrical distance is the key electrical index in AC/DC power system, which is of great significance to the planning, construction and operation of power system. However, the results obtained by different calculation methods are often not equal or even different. This paper describes the principle of the existing representative calculation methods for electrical distance calculation, and analyzes the reasons for the different calculation results of these methods. Aiming at the defects of some algorithms in principle, an improved algorithm is proposed. Finally, the following results are obtained: (1) The concept of classical electrical distance is extended to AC/DC power system, and a sensitivity based electrical distance calculation method is proposed.(2) Aiming at the shortcomings of the existing transient method, an improved transient method is proposed.(3) The sensitivity method proposed in this paper can reflect the influence of the topological structure and the DC control mode on the electrical distance under small disturbance; The transient method proposed in this paper can reflect the influence of topological structure, DC control mode and stability parameters on electrical distance under large disturbance.