Simulation method and device for monopole grounding fault arc model

Abstract

The invention discloses a simulation method and device for a single-pole grounding fault arc model. The method is applied to a true bipolar flexible direct current system, in the method, a primary arc theory and a secondary arc theory are combined, an arc model is constructed, the dynamic change characteristics of a fault arc are simulated in PSCAD through fault branch arc current and arc voltage, and the dynamic change characteristics comprise the nonlinear characteristic and the self-extinguishing characteristic. According to the application, the arc current and the arc voltage are taken as the input quantity of the arc model, the arc resistance is calculated and output through the arc model, and is fed back to the fault branch as the resistance value of the nonlinear resistor, so that the arc resistance values of different stages are simulated, and the simulation of the arc self-extinguishing characteristic is realized; the non-linear characteristic of the arc is embodied by the arc current and the arc voltage. The extinguishing moment of the arc is obtained according to an actual application scene in the simulation process, and the unipolar grounding fault arc characteristics of the true bipolar flexible direct current system can be simulated more truly.

Description

Technical field [0001] The present application relates to the technical field of power system fault simulation, and in particular to a simulation method and device for a single-pole ground fault arc model. Background technique [0002] Flexible DC transmission has been widely concerned and studied by domestic and foreign scholars in recent years due to its advantages of flexible power flow control and difficulty in commutation failure. Flexible DC overhead transmission lines have been exposed to the outdoors for a long time and have harsh working conditions, making them prone to faults. Single-pole grounding transient faults have the highest probability of occurrence. For a true bipolar flexible system, after a single-pole ground fault occurs, the other pole is still energized, which will provide an energy source to maintain arc combustion for the faulted pole after the circuit breaker is disconnected through coupling until the energy provided is insufficient. When the arc ...

AI Technical Summary

Problems solved by technology

[0006] This application discloses a simulation method and device for a unipolar ground fault arc model, which is used to solve the problem of using a constant impedance model instead of an arc model on a PSCAD platform to simulate a unipolar ground fault in a true bipolar flexible straight system in the prior art. The constant impedance model cannot simulate the nonlinear characteristics of the fault arc, and the extinguishing time of the arc is artificially preset, which is a technical problem with poor authenticity

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