Abstract:  ABSTRACT： With the broadly application of high power electronic converters in power system, modeling and stability analysis of power system are becoming ever more challenging. Firstly, this paper proposes a small-signal modeling method for AC/DC power system based on transfer matrix concept, whose characteristic is explicitly defining a controlled object of a power system as the so-called Jacobian transfer matrix （JTM）. Secondly, this paper establishes a power system with an AC voltage source connected with a voltage source converter （VSC）. By applying JTM modeling method, it can be found that JTM is appropriate for low frequency stability of power system. In addition, with the increase of load angle, the zero of JTM moves to origin, and the trajectory corresponds to the power angle and voltage stability boundary in phasor method. Then, to study power system resonance, JTM modeling method is used to build a small-signal model of system. The resonance pole is provided with virtual damping by a high-pass filter HHP（s）. The result shows that, with the increased current control gain of HHP（s）, the resonance poles of JTM are shifted to the left half-plane and the system stability is improved. Meanwhile, the damping effect is applicable to any resonance frequency of AC system.

Key words:  AC/DC power system, Jacobian transfer matrix （JTM）, stability, feedback control, pole-zero, high-pass filter, virtual resistor