Building method and device for homopolar crossing fault model between DC systems

Abstract

The embodiment of the invention provides a building method and device for a homopolar crossing fault model between DC systems, and relates to the field of a power system. By the building method and device, an equivalent model of the homopolar crossing earth-free fault between the DC systems can be built. The building method comprises the steps of acquiring a homopolar crossing earth-free fault model by a David equivalent value; simulating the earth-free fault model to obtain a first network topological map and a second network topological map; building a first boundary equation set and a second boundary equation set according to the first network topological map, the second network topological map and a preset rule; acquiring trigger angle values of conversion stations in the first networktopological map and the second network topological map according to a simulation result of the earth-free fault model; building a homopolar crossing earth-free fault equivalent model; and calculatinga fault equivalent impedance value of the homopolar crossing earth-free fault equivalent model according to the trigger angle values of the conversion stations in the first network topological map and the second network topological map, the first boundary equation set, the second boundary equation set and an equation set between a preset rectification side and an inversion side.

Description

technical field [0001] The invention relates to the field of power system analysis, in particular to a method and device for establishing a homopolar crossover fault model between direct current systems. Background technique [0002] DC engineering has obvious advantages in power transmission. In recent years, most of the large-capacity long-distance power transmission in my country has begun to adopt the form of DC transmission. According to the plan, there will still be a large number of long-distance high-voltage direct current transmission projects to start construction in the future. Due to the reverse distribution of my country's main energy bases and load centers, the planned transmission lines are mostly north-south or east-west. With the increase of the number of lines, the crossover of DC and DC transmission lines will be inevitable, and the probability of DC-DC crossover short-circuit faults will increase accordingly. DC-DC crossover is a complex type of fault, ...

AI Technical Summary

Problems solved by technology

Electromagnetic transient simulation can simulate the detailed dynamic process of DC and its control system in detail, but the calculation scale and calculation time required for the overall electromagnetic transient simulation are relatively large; and electromechanical transient simulation is an important part of the analysis and calculation of power system safety and stability. Its application involves the whole process of power production such as power grid planning, scheduling, mode formulation and post-event inversion analysis. Therefore, it is necessary to study a DC-DC crossover fault analysis and calculation method suitable for electromechanical transient simulation

[0003] However, in the existing technology, there are few overall research and analysis on DC-DC cross-over ungrounded faults, and the analysis methods for DC systems, whether traveling wave theory or switching function method, are difficult to apply to DC-DC cross-over ungrounded faults. In the electromechanical transient analysis, it cannot meet the analysis needs of DC-DC crossover ungrounded faults in engineering

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