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Analysis And Calculation Of The Short-Circuit Current Of Xiamen VSC-HVDC Project

For the heavy load urban power grid, the short-circuit current is closed to the breaking capacity of the AC breaker. After the voltage sourced converter high voltage direct current (VSC-HVDC) is connected, the short-circuit current of VSC-HVDC will be provided during the fault period, which will cause the short-circuit current exceed the standard value and affect the normal operation of the power grid. Taking the Xiamen VSC-HVDC project as an example, this paper analyses the VSC-HVDC control mode, obtains the short-circuit current calculation method. The Xiamen AC / DC hybrid model is built, and the correctness of the proposed method is verified by simulation. The results show that the amplitude and phase angle of the VSC-HVDC short-circuit current have great influence on the total short-circuit current, and the amplitude is easily controlled by the current limiting controller, so the phase angle control should be emphasized. For Point of Common Coupling (PCC), the short-circuit current of single-phase grounding fault may be larger than three-phase grounding fault, which should be taken into account. The ideas provided in this paper have practical engineering significance for the city power supply by VSC-HVDC.