Study on DC power modulation in AC/DC power system

The influence of DC power modulation on transient stability for an interconnected AC/DC power system is studied and some regularity conclusions are made in this paper. The engineering feasibility and existing problems of improving the transient stability by fast DC power modulation is also studied when the AC system is subjected to a large disturbance. Moreover, it is discussed whether DC power modulation absorbs a large amount of reactive power, and possibly leads to voltage collapse of the AC system. The simulation results prove that the effectiveness of DC power modulation to improve the transient stability of an interconnected AC/DC power system is subject to the network structure of the system, the parameters and reactive power characteristics in the AC system, the types of modulator, their parameters and the operation mode in the DC system