Dynamic modeling and control of three phase pulse width modulated power converters using phasors

Although the application of power electronic converters in ac power systems has been mostly limited to unidirectional loads like motor drives, various evolving applications such as power quality conditioners and distributed generation systems feature complex dynamic interactions affecting the operation of the ac power system. The focus of this paper is to present systematic technologies for modeling switching power converters in conjunction with their controls to determine their dynamic properties and assess their performance in an ac power network. The paper presents a dynamic phasor-oriented modeling technique that is readily compatible with classical power system analysis techniques. A state space model that represents the dynamic properties of the system in the magnitude-angle form is developed. The model can be used for obtaining steady state small signal dynamic properties at various operating conditions, and hence be used for design of appropriate regulators. Application of the technique is illustrated using a current source inverter example.