Research on evolvement approach of multiple stability forms and AC/DC coordinated control strategy in large power grid

Multiple stability forms such as angle stability, volt-age stability and frequency stability may occur under severe faults in large power grid. In this paper, impacts on the interactive evolvement of multiple stability problems are studied and quantified, which are brought by relevant factors such as the fault severity, load model and DC control mode. In addition, AC/DC coordinated control strategy is proposed under the condition that multiple stability forms coexist on the basis of theoretical analysis, which can get the per unit model of control strategy of generating unit tripping, load shedding, DC modulation, etc, and the method proposed above can enhance the applicability of dealing with multiple stability problems at the same time. Finally, simulation study on the actual electric net-work is presented to verify the effectiveness and advantage of the proposed AC/DC coordinated control strategy.